Dental amalgam.



ca 1.164.997 SR FATE T THOMAS JAMES DAVIS, OF NEW YORK, N. Y.

"DENTAL AMALGAM.

No Drawing.

To all whom it may concern Be it known that I, THOMAS J. DAVIS, acitizen of the United States, and resident of the borough of Brooklyn,county of Kings, city and State of New York, have invented certain newand useful Improvements in Dental Amalgam, of which the following is aspecification.

The object of this invention is to materially improve the generalcombination of metals or alloys as they are commonly termed, that areemployed in dental surgery, and although it may appear that myimprovement consists merely in changing the appearance of the alloy inits non-amalgamated state, I have a further object and that is to provethe presence of a finer metal such as gold in the allow used.

Usually dental alloys 01' amalgams consist of certain desirablequantities of silver, copper, zinc, and other metals such as aluminum orbismuth, the combination being determined entirely by the requirements,and in each alloy it has been customary to include a certain quantity ofgold, so that the result would be a non-oxidizing metallic substance. Asordinarily formed these alloys or a malgams have the appearance gf smallgranuEs fog flakes of a whitish gray color possibly due to the presenceof mercury by which the metals are amalgamated. In this. its commonstate, it is quite apparent that the presence of gold can only bedetermined by certain chemical tests.

It is not always possible or desirable for the dental operator to testthe alloy presented to him for use, and even though the operator were toconvince himself by test that a desirable quantity of gold was containedin the alloy, the lack of chemical knowledge on the part of the averagepatient makes it quite impossible for the operator to convince thepatient of the presence of gold within the alloy.

The use of gold in dental amalgams or alloys is not merely for itsappearance, in

I fact, when the alloy is amalgamated by the operator for the purpose ofmaking it plastic just prior to its use, the mercury surrounding all ofthe metals, will change their color to a gray, White, or silver color,and even after the mercury has been removed by pressure and the amalgamplaced in the cavity of a tooth, its appearance will continue toincrease in whiteness to a definite extent, but

Specification of Letters Patent. 7 Patented Dec, 1915 Application filedDecember 8, 1914. Serial No. 876,085.

under no conditions has it been found to assume the brilliant goldcolor.

The gold is used in the amalgam for the purpose of producing atough,non-oxidizing filling and one upon which the acids of the mouth willhave no effect. The gold further assists in preventing tl i e a l l oy fro m shrinking-"away fr'onrtfie cavity, and also assists in producingthe desired hardness and strength of the alloy. It may be further notedthat the presence of gold also insures that the alloy will not discolorthe tooth in which it is inserted. It is evident, then, that it becomesimportant for the operator and patient to know definitely that gold ispresent in the alloy, and to establish this fact, in the alloy that Iproduce I omit a portion of the gold from the combination of metalsduring the production of the base of the alloy, later adding it in amanner that will make its presence easily appreciated.

In producing my alloy I f 1 1 s e or amalgamate together certaindesirable quantities, of baser metals such as, wper si l er z i ng aluminumwr other deslrable metallic substances in certain quantities to bedetermined by the ultimate use of the alloy.. I thg granulate or flakethe alloy by filing or shaving. I then submit the alloy to a chemicalaction in the presence of heat, or to an,eleotrsrohemicaliaction withoutheat. In each of these actions pure gold is brought into close proximitywith the alloy, and a surface of gold.. isi-ideposited .u-pon eachigazanuleaor flake of alloy.

It is my desire that each granule or flake of the alloy shall beentirely incased Withinan envelop of gold, and to accomplish this I havefound it desirable to agitate the gold and alloy during the chemical orelectrochemical action. After the gold is deposited the alloy may beslightly warmed and bur- "'i1ished.* It will be apparent, however, thatthe warming during the burnishing will not be necessary if a purelychemical action has beiial employed for the depositing of. the} go V r vThe result of my operation is the production of an alloy of a rich goldcolor, an alloy 4 that will not tarnish when submitted to atmosphericconditions, and one that will by its appearance prove the presence ofthe desirable quantity of the finer metal.

In operating with my alloy the ordinary method will be found entirelysatisfactory.

strata should be" placed in the cavity and there allowed to hardenasbefo-re set forth. The color, appearance, effect, and wearingqualities of my alloy will be the same as that of any high-grade alloyin which the presence of gold is an assured fact.

It will be appreciated that modifications may be made within the scopeof the appended claims without departing from the principle orsacrificing the advantages of this invention.

Having-carefully and fully described my invention, what I claim anddesire to secure by Letters Patent is:

l. A dental alloy subdivided into granules and a casing of non-oxidizingmetal for each said granule. asand for the purpose set forth.

2. A dental amalgam consistingof metallic substances divided intogranules and a metallic casing for each said granule as and for thepurpose set forth.

3. A dental amalgam consisting of an alloy of metallic substancessubdivided into granules, and a metallic casing for each said granule asand for the purpose set forth.

4. A dental alloy of metallic substances subdivided into granules and acasing of gold for each said granule as and for the purpose set forth.

5. A dental amalgam consisting of an al loy of metallic substances oneof which is gold, said alloy being sub-divided into granules and a .sasii saimsa or, Said rgran ule as and for the pur fidse set forth.

'Signed at borough of Manhattan, county of New York, city and State ofNew York, this 18th day of November, 1914.

THOMAS JAMES DAVIS. W'itnesses:

AUGUs'rUs A. Wns'r, ARTHUR PHELPS MARK.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

